Interaction between silver nanoparticles (AgNPs) and iron plaque, which forms at the root surface of wetland plants under waterlogging conditions, is a critical process that controls the bioavailability of AgNPs. In this study, we comparatively evaluated how and to what extent iron plaque affected silver uptake sourced from metallic (Ag⁰NPs) and sulfidized (Ag₂S-NPs) silver nanoparticles under hydroponic conditions. After the formation of iron plaque at the root surface upon exposure to Fe²⁺ at 0–100 μg mL⁻¹, rice (Oryza sativa L.) seedlings were transferred to AgNP suspensions. Silver uptake depended on the amount of iron plaque and AgNP species (Ag⁰NPs vs. Ag₂S-NPs): Ag₂S-NP exposure had lower or comparable Ag uptake to that of Ag⁰NP exposure at low levels of Fe²⁺ (0–80 μg mL⁻¹), but significantly higher Ag uptake at 100 μg Fe²⁺ mL⁻¹. Such contrasting effects of iron plaque on the bioavailability of Ag⁰NPs and Ag₂S-NPs were attributed to their influences on AgNP dissolution. However, the translocation factors (TFs) and particle size distribution of NPs in planta (as determined by single-particle inductively coupled plasma-mass spectrometry analysis) were not affected by the amount of iron plaque. These results reveal contrasting effects of iron plaque on the bioavailability of Ag⁰NPs and Ag₂S-NPs, and raise concerns about the exposure of wetland plants to Ag₂S-NPs in Fe-rich environments, where high Fe levels may facilitate Ag₂S-NP bioavailability.

Microplastics are ubiquitous in marine environments. Sediments and marine organisms are recognized as the carriers and final destinations of microplastics. However, research on the concentration and abundance of microplastics in deep-sea sediments and organisms is limited. In this study, samples of sediments and organisms were collected from deep-sea locations of the western Pacific Ocean, with the depth ranging from 4601 m to 5732 m. Microplastics were extracted from the samples and analyzed by micro-Fourier-transform infrared spectroscopy. The average abundance of microplastics in the sediments was 240 items per kg dry weight of sediment. The microplastics were predominantly fibrous in shape (52.5%), blue in color (45.0%), and less than 1 mm in size (90.0%). The most commonly detected polymers were poly(propylene-ethylene) copolymer (40.0%) and polyethylene terephthalate (27.5%). The concentrations of polychlorinated biphenyls (PCBs), which are representatives of persistent organic pollutants, in the pore water of sediment samples were also investigated. A significant correlation between the distribution of microplastics and the PCB concentrations in sediments was found (P = 0.016). Microplastics were also detected in deep-sea organisms (i.e., Crinoidea, Pheronematidae, Ophiuroidea, and Gammaridea) in the sampling region, with an abundance of 0–3 items per individual biological sample. This assessment of microplastics in deep-sea sediments and benthic organisms of the western Pacific Ocean confirms that microplastic pollution exists in the deep-sea ecosystems of this region.

Animal studies have suggested that phthalate exposure alters the fatty acid composition of blood plasma. Therefore, we conducted an epidemiological study to examine whether urinary concentrations of phthalates are correlated with circulating fatty acids in the general US population. The 2003–2004 and 2011–2012 National Health and Nutrition Examination Survey were used in this study. Ten urinary phthalate metabolites and 23 fatty acids were measured. Fatty acid patterns were identified using principal component analysis (PCA) with an eigenvalue greater than 1. A two-step analysis was performed. We first performed multivariable linear regressions to evaluate whether urinary phthalate metabolites were related to the PCA-derived components of blood fatty acid levels. Then we performed multivariable linear regressions to investigate each of the fatty acids that were suggestively correlated with some of the phthalates in PCA. There were 994 participants (51.91% women). As for men, after adjustments for potential confounding factors, MECPP, MEHHP, and ∑DEHP were all positively correlated with gamma-linolenic, myristoleic, and myristic acids; both MEHHP and ∑DEHP were positively correlated with stearic acid; MMP was positively correlated with docosahexaenoic acid. As for women, MMP was negatively correlated with docosanoic, lignoceric, and arachidic acids; MBzP was negatively correlated with docosahexaenoic acid; both MEHP and MCPP were negatively correlated with docosatetraenoic acid; MEHP was negatively correlated with arachidonic acid, and MCPP was negatively correlated with docosapentaenoic-6 acid. Our findings support that phthalates may be correlated with circulating fatty acids.

Maternal nicotine exposure during lactation induces liver damage in adult male rats. However, the mechanism in males is unknown and females have not been tested. Here, we determined the liver lipid composition and lipogenic enzymes in male and female offspring at two ages in a model of postnatal nicotine exposure. Osmotic minipumps were implanted in lactating Wistar rat dams at postnatal day (PND) 2 to release 6 mg/kg/day of nicotine (NIC group) or saline (CON group) for 14 days. Offspring received a standard diet from weaning until euthanasia at PND120 (1 pup/litter/sex) or PND180 (2 pups/litter/sex). At PND120, NIC males showed lower plasma triglycerides (TG), steatosis degree 1, higher hepatic cholesterol (CHOL) ester, free fatty acids, monoacylglycerol content as well as acetyl-coa carboxylase-1 (ACC-1) and fatty acid synthase (FAS) protein expression in the liver compared to CON males. At this age, NIC females had preserved hepatocytes architecture, higher plasma CHOL, higher CHOL ester and lower total CHOL content in the liver compared to CON females. At PND180, NIC males showed steatosis degrees 1 and 2, higher TG, lower free fatty acids and total CHOL content in the liver and an increase in ACC-1 hepatic protein expression. NIC females had higher plasma TG and CHOL levels, no change in hepatic morphology, lower CHOL ester and free fatty acids in the liver, which also showed higher total ACC-1 and FAS protein expression. Maternal nicotine exposure induces long-term liver dysfunction, with an alteration in hepatic cytoarchitecture that was aggravated with age in males. Concerning females, despite unchanged hepatic cytoarchitecture, lipid metabolism was compromised, which deserves further attention.

The accuracy and reliability of volatile organic compound (VOC) emission data are essential for assessing emission characteristics and their potential impact on air quality and human health. This paper describes a new method for determining VOC emission data by multipoint sampling from various process units inside a large-scale refinery. We found that the emission characteristics of various production units were related to the raw materials, products, and production processes. Saturated alkanes accounted for the largest fraction in the continuous catalytic reforming and wastewater treatment units (48.0% and 59.2%, respectively). In the propene recovery unit and catalytic cracking unit, alkenes were the most dominant compounds, and propene provided the largest contributions (57.8% and 23.0%, respectively). In addition, n-decane (12.6%), m,p-xylene (12.4%), and n-nonane (8.9%) were the main species in the normal production process of the delayed coking unit. Assessments of photochemical reactivity and carcinogenic risk were carried out, and the results indicate that VOC emissions from the propene recovery unit and catalytic cracking unit should be controlled to reduce the ozone formation potential; in addition, alkenes are precedent-controlled pollutants. The cancer risk assessments reveal that 1,2-dibromoethane, benzene, 1,2-dichloroethane, and chloroform were the dominant risk contributors, and their values were much higher than the standard threshold value of 1.0 × 10⁻⁶ but lower than the significant risk value defined by the US Supreme Court. Based on the VOC composition and a classification algorithm, the samples were classified into eight main groups that corresponded to different process units in the petroleum refinery. In conclusion, this work provides valuable data for investigating process-specific emission characteristics of VOCs and performing associated assessments of photochemical reactivity and carcinogenic risk in petrochemical refineries.

Smoked cigarette filters a. k.a. “butts”, composed of plastic (e.g. cellulose acetate) are one of the world’s most common litter items. In response to concerns about plastic pollution, biodegradable cellulose filters are being promoted as an environmentally safe alternative, however, once smoked, both contain toxins which can leach once discarded. The impacts of biodegradable butts as littered items on the receiving environment, in comparison with conventional butts has not yet been assessed. A freshwater mesocosm experiment was used to test the effects of leachate from smoked cellulose acetate versus smoked cellulose filters at a range of concentrations (0, 0.2, 1 and 5 butts L⁻¹) on the mortality and behaviour of four freshwater invertebrates (Dreissena polymorpha, Polycelis nigra, Planorbis planorbis and Bithynia tentaculata). Leachate derived from 5 butts L⁻¹ of either type of filter caused 60–100% mortality to all species within 5 days. Leachate derived from 1 butt L⁻¹ of either type resulted in adults being less active than those exposed to no or 0.2 butts L⁻¹ leachate. Cigarette butts, therefore, regardless of their perceived degradability can cause mortality and decreased activity of key freshwater invertebrates and should always be disposed of responsibly.

This study investigates the influence of meteorology, land use, built environment, and traffic characteristics on near-road ultrafine particle (UFP) concentrations. To achieve this objective, minute-level UFP concentrations were measured at various locations along a major arterial road in the Greater Toronto Area (GTA) between February and May 2019. Each location was visited five times, at least once in the morning, mid-day, and afternoon. Each visit lasted for 30 min, resulting in 2.5 h of minute-level data collected at each location. Local traffic information, including vehicle class and turning movements, were processed using computer vision techniques. The number of fast-food restaurants, cafes, trees, traffic signals, and building footprint, were found to have positive impacts on the mean UFP, while distance to the closest major road was negatively associated with UFP. We employed the Extreme Gradient Boosting (XGBoost) method to develop prediction models for UFP concentrations. The Shapley additive explanation (SHAP) measures were used to capture the influence of each feature on model output. The model results demonstrated that minute-level counts of local traffic from different directions had significant impacts on near-road UFP concentrations, model performance was robust under random cross-validation as coefficients of determination (R²) ranged from 0.63 to 0.69, but it revealed weaknesses when data at specific locations were eliminated from the training dataset. This result indicates that proper cross-validation techniques should be developed to better evaluate machine learning models for air quality predictions.

The imprudent agricultural practices are leading to an increasing load of pesticides in agricultural fields. Thus, there is a need to minimize the harmful effect of pesticides by adopting sustainable strategies. In the recent past decade, kinetin, a plant synthetic hormone, has been reported as a pesticide toxicity alleviator in higher plants. But its role in mitigating pesticide toxicity in cyanobacteria is still limited. Thus, in current study an attempt has been made to investigate the potential of kinetin in regulating cypermethrin, an insecticide, induced toxicity in Anabaena PCC 7120 and Nostoc muscorum ATCC 27893. Cypermethrin (Cyp₁; 2 μg ml⁻¹ and Cyp₂; 4 μg ml⁻¹) showed negative impact on growth, photosynthetic pigments, photosynthetic O₂-evolution and primary photochemistry of PS II (Phi_P₀, Psi_₀, Phi_E₀) resulting in decrease in performance index (PIABS). However, under similar conditions, increases in energy flux parameters (ABS/RC, TR₀/RC, ET₀/RC and DI₀/RC) were noticed. Cypermethrin at both the doses enhanced the level of oxidative stress biomarkers (SOR, H₂O₂, and MDA equivalent contents) despite of increased antioxidant enzymatic activity (SOD, POD, CAT and GST).Under similar condition, cypermethrin at tested doses caused substantial decrease in non-enzymatic antioxidant contents (proline, cysteine and NP-SH). Nevertheless, kinetin treatment attenuated cypermethrin induced oxidative stress by further up-regulating the activity of enzymatic antioxidants and by enhancing the contents of non-enzymatic antioxidants. Thus, with the application of kinetin improved photochemistry of PS II and growth yield of both the cyanobacteria were observed even in the presence of cypermethrin. Current results establish that cypermethrin induces toxicity on photosynthesis, photosynthetic pigments and growth, and this effect was more pronounced in Anabaena PCC 7120 than Nostoc muscorum ATCC 27893. Furthermore, the potential role of kinetin in mitigating the toxicity of cypermethrin in both the cyanobacteria provides an insight to be used in paddy fields for sustainable agricultural practices.

Oxidative stress is considered a main commonly reported mechanism of nanoparticles toxicity, so this study aimed to evaluate oxidative stress and biochemical alterations in the haemolymph and digestive gland of snail, Monacha cartusiana exposed to sublethal concentrations of zinc oxide nanoparticles (ZnONPs) for 14 days (d). The results indicated that, ZnONPs induced significant increases in lipid peroxidation (LPO) and lactate dehydrogenase (LDH) in treated animals and did not return to normal levels after recover period. A significant decline of glutathione peroxidase (GPx), glutathione-S-transferase (GST) activities, and glutathione (GSH) content in the haemolymph and digestive gland of snails was observed when compared with control. A significant increase was observed in catalase (CAT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activities of treated animals. In general, nano-materials are able to induce oxidative stress in exposed animals. The present findings indicate that, alterations of antioxidant enzyme activities, increase of LPO, LDH, and reducing of GSH content and GST, GPx activities are recognized to oxidative stress and cell damage. This species could be considered a good bioindicator to assess nano-materials exposure.

No information is available on the long-term effects on thyroid and growth hormones of children exposed to phthalate-tainted products, despite the infamous 2011 Taiwan phthalate episode. We investigated estimated daily intake levels and their long-term effects on serum thyroid and growth hormone levels in children.We recruited 166 children (2–18 years old) in three visits who provided specimens and filled out a questionnaire from the Risk Assessment of Phthalate Incident in Taiwan (RAPIT) project study from 2012 to 2016. Morning spot urine samples were analyzed for nine phthalate metabolites. Serum thyroid (triiodothyronine [T₃], thyroxine [T₄], and free T₄) and growth hormone (insulin-like growth factor-1 [IGF-1] and its binding protein 3 [IGF-BP3]) levels were measured. A generalized estimating equation model was used to evaluate associations between phthalate metabolite levels and children’s thyroid and growth hormone levels.The median metabolite levels of monomethyl phthalate (MMP), Σdibutyl phthalate (DBP), and Σdi-(2-ethylhexyl) phthalate (DEHP) at visits 1, 2, and 3 were 6.59, 10.5, and 21.0 ng/mL, 0.15, 0.24, and 0.20 nmol/mL, and 0.15, 0.17, and 0.12 nmol/mL, respectively. After adjusting for potential confounding factors, we found that levels of urinary MMP were negatively associated with T₃ (β = −0.013, p = 0.047), T₄ (β = −0.016, p = 0.006), free T₄ (β = −0.012, p = 0.002), and IGF-BP3 (β = −0.025, p = 0.003). Urinary mono-ethyl phthalate (MEP) was negatively associated with IGF-1 (β = −0.027, p = 0.029) and IGF-BP3 (β = −0.016, p = 0.018). In addition, serum free T₄ was positively associated with urinary mono-2-ethyl-5-hydroxy hexyl phthalate (MEHHP) (β = 0.016, p = 0.043), mono-2-ethyl-5-oxohexyl phthalate (MEOHP) (β = 0.015, p = 0.024), and ΣDEHPm (β = 0.019, p = 0.020).Our findings support the hypothesis that specific phthalates disturb the hemostasis of thyroid and growth hormone levels in children exposed to phthalate-tainted products.